Hello, looking around I found this possible solution for you:
Go to your settings > network access
You should find "connectivity", you want to set this to always allowed then try reconnecting to the internet.
Alternatively, you can try a soft reset by entering the code *#7780# into your device keypad and reset the settings on it. When prompted for a security code, by default it should be 12345 or if you have changed this, it will be the code you changed it to.